Yamha cooling water

[Pelagic Captain]

I have T 9.9 trolling motor on one boat and a T8 on another. Both run great, start easy and warm up fast. The question is ..the cooling water from the squirt tube is not much warmer than the raw water going in. Both engines discharge all the time, unlike my merc. that comes on and off as you would expect a thermostat control to do . This no big deal although it would be nice to have warm water for a hot box . Is this a normal thing for yamaha's. ??

Thanks Bob

[Hoghunter]

Originally Posted by Pelagic Captain

I have T 9.9 trolling motor on one boat and a T8 on another. Both run great, start easy and warm up fast. The question is ..the cooling water from the squirt tube is not much warmer than the raw water going in. Both engines discharge all the time, unlike my merc. that comes on and off as you would expect a thermostat control to do . This no big deal although it would be nice to have warm water for a hot box . Is this a normal thing for yamaha's. ??

Thanks Bob

Yup that's normal, they squirt all the time. My water squirt is warmer than the 50 to 55 degree seawater going in though. The higher your rpm the warmer the discharge water becomes. I usually troll at around 3200 to 3700 rpm's so mine is certainly warmer than seawater.

[Road Rage]

Originally Posted by Pelagic Captain

I have T 9.9 trolling motor on one boat and a T8 on another. Both run great, start easy and warm up fast. The question is ..the cooling water from the squirt tube is not much warmer than the raw water going in. Both engines discharge all the time, unlike my merc. that comes on and off as you would expect a thermostat control to do . This no big deal although it would be nice to have warm water for a hot box . Is this a normal thing for yamaha's. ??

Thanks Bob

On today's Yamaha motors, the water out of the "pee hole" is really just an indicator that the impellor is pumping water. This water does not actually cool the engine. The cooling water exits through the hub of the prop.

If you want a hot box, you'll have to drill and tap a fitting into the t-stat housing... or have your service dept do it for you. Cost me about $50 to have it done on my Merc 9.9, which uses the same power head as the Yamaha.